Many reinforced, flexible hoses have at least three layers, at least one being a reinforcing layer. The reinforcing layer is typically either a layer of braided or woven cord or a helically wound reinforcement. In making the reinforced, flexible hose, a first elastomeric layer is formed into the shape of a tube by applying elastomeric material to a mandrel. This first elastomeric layer is generally smooth but may be textured or contoured. Another elastomeric layer forms at least a portion of the external surface of the hose. The external surface of the hose may be a smooth surface, may be textured, or may have a helical winding.
Reinforced, flexible hoses are very durable, making them very useful in certain applications, such as on tank trucks. However under certain conditions, the hoses can be very difficult to control and maneuver. For example, when the external surface of the hose becomes moist, it becomes very slippery and the hose becomes difficult to maneuver. This is especially true when larger diameter hoses with smooth external surfaces are being used.
To help in controlling and maneuvering a hose, many operators will add an external handle to the hose. Generally, these handles are clasped to the external surface of the hose. When clasping a handle to a hose, care must be taken to assure the handle does not slip on the external surface of the hose. As a result, the handle must be either attached so that it firmly squeezes the hose or the handle clasp must contain grips that dig into the external surface of the hose to hold the handle in place.
Attaching a handle in either of these ways may result in damage to the hose. Attaching the handle to firmly squeeze the hose may provide excess strain in a concentrated area of the hose. Attaching a handle containing grips may damage the hose because the grips may dig into the hose layers and may result in excess stress in a concentrated area of the hose. Additionally, the edges of the clasp when tightened onto the hose may cut into the hose surface causing further damage to the hose. An operator using a hose having an external handle may be injured as a result of this damage to the hose. Since most reinforced, flexible hoses are used in either pressure or vacuum applications, the damage to the hose may reduce the pressure or vacuum tolerance of the hose. As a result, the likelihood of hose failure during operation increases. Hose failure during a pressure or vacuum operation may result in injury to the operator, especially when a harmful product is being transported through the hose.
An addition problem resulting from adding an external handle is that the clasps reduce the flexibility of the hose in the area where the clasp is attached. Since the clasp is likely a solid ring that extends around the circumference of the hose, the flexibility of the hose is reduced at the location of this solid ring.